Introduction | Background
| Chloramines
& Chlorine If
You Are On Dialysis| If
You Own Fish| Q&A
| Glossary Water
Quality Reports
Tampa Bay Water Changes its Disinfectant
Residual
In 2002, Tampa
Bay Water will stop using chlorine as its disinfectant
residual and will begin using chloramines in its treatment of
drinking water. After initial treatment with a primary
disinfectant, small amounts of a secondary disinfectant,
or disinfectant residual, must be applied and maintained
at all times within the distribution system to kill
organisms that could make people sick. Tampa Bay Water
will use chloramines as its secondary disinfectant and
continue to use chlorine as its primary
disinfectant.
While Tampa Bay Water already
complies with all current water quality regulations,
this change is being made in advance of new, stricter
health standards expected to be imposed in the future
under the national Safe Drinking Water Act. Chloramines
were selected as the method of choice because they are
the most cost-effective way of maintaining compliance
under the new regulations. The use of chloramines is 20
percent less expensive than alternative methods of
treatment, and at the same time reduces the formation of
suspected cancer-causing compounds. And, by switching to
chloramines, a more consistent water quality will be
maintained throughout Tampa Bay Water's wholesale
system.
The use of chloramines as a secondary
disinfectant is not a new process and has been used for
decades in many cities and counties across the country.
In fact, 20-25 percent of the local governments within
the United States currently use chloramines, and the
number is expected to grow due to new regulations.
Cities like Denver and Minneapolis have been using them
since World War II. In Florida, chloramines are used in
30 utilities, including the Miami-Dade area of south
Florida.
The change to chloramines will
reduce the level of some regulated disinfection
by-products formed when chlorine mixes with trace
quantities of naturally occurring organic substances
found in water. This is particularly significant because
the use of chloramines will reduce the formation of
trihalomethanes (THMs) and haloacetic acids (HAAs), two
types of by-products suspected to cause cancer with
prolonged exposure.
This change will not
impact all Tampa Bay area residents in the same way. Any
noticeable changes will depend on the type of final
disinfectant each member
government chooses to use and whether the chosen
treatment differs from that member government's existing
practices. A final disinfectant is necessary because the
residual decreases with time and may disappear
completely.The following is a list of anticipated
changes:
• The City of Tampa already adds
chloramines to it water as a final disinfectant, so its
customers will not notice a change. •
Hillsborough County began providing chloraminated
water to residents of north Hillsborough County in
October 2001 and will continue providing water treated
with free chlorine to residents of south-central
Hillsborough County for the next few years, so only some
of its residents may notice a change. •
Pinellas County, Pasco County and the
City of St. Petersburg will begin treating their
water with chloramines, so their residents may notice a
change. • New Port Richey, along
with certain other areas that receive water from
isolated sources, won’t receive any chloraminated water
from Tampa Bay Water, so those residents will not be
affected.
Municipalities
that purchase water from Tampa Bay Water’s members
(listed above) will be affected
accordingly.
Those member governments that do
switch to chloramines as a final disinfectant will need
to make some equipment changes at their treatment
facilities
Residents who will be receiving
chloraminated water for the first time may notice a
change in taste or odor. Chlorine will become much more
difficult to detect. Other temporary impacts may be
noticed in isolated areas as the chloraminated water is
introduced into the member governments' retail
distribution systems. Some customers may notice a
temporary variation in water color as well as possible
sediment in the water. These temporary impacts to water
quality are similar to those experienced when a water
main is replaced or routine maintenance is performed on
the water distribution system and will cease as the
system stabilizes.
Chloramines, like
chlorine, must be removed from water before it is used
for two specific purposes. Those purposes
include:
-- Kidney dialysis treatments
and -- Keeping live fish, such as in an
aquarium or pond
Since the process for removing
chloramines is different from some of the methods used
to remove chlorine, medical facilities and dialysis
units, as well as pet shops, seafood merchants,
restaurant managers and area attractions featuring
marine life will be notified in ample time to prepare
for the conversion. (For more detailed information click
If
You Are On Dialysis or If
You Own Fish.)
As this change will affect
many people in the Tampa Bay region, some background
on Tampa Bay Water and its operations may be
helpful.
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